Recent research indicates that idiosyncratic facial movements can provide a route to facial identity (review in Roark et al., 2003), but it is unclear whether recognizing a face by its idiosyncratic facial movements involves the same neural mechanisms that are involved in recognizing a static face image. Here we report the results from a developmental prosopagnosic (CS), who, whilst being severely impaired at recognizing static faces, can discriminate between dynamic identities (experiments 1a & 1b) and learn to name individuals on the basis of their idiosyncratic facial movements (experiment 2). Across 3 experiments, CS's ability to use idiosyncratic facial motion as a cue to identity was either comparable to (experiments 1a and 2) or significantly better than (experiment 1b) that of matched and undergraduate control groups. CS's superior performance in experiment 1b may reflect a dependence on motion information as a compensatory strategy to recognize people around him. This dissociation between an impairment in using static facial information to compute identity, and preserved ability in using idiosyncratic facial motion information to compute identity, indicates that the neural mechanisms involved in recognizing a static face image may be dissociable from those involved in recognizing an individual on the basis of their idiosyncratic facial movements.